def initialize_subclassed_issue_tracker
      # set the app's issue tracker
      if params[:app][:issue_tracker_attributes] && tracker_type = params[:app][:issue_tracker_attributes][:type]
        if IssueTracker.subclasses.map(&:name).concat(["IssueTracker"]).include?(tracker_type)
          app.issue_tracker = tracker_type.constantize.new(params[:app][:issue_tracker_attributes])